In Chicago, the with + null object construction is not limited
to `come/go', and it has certainly spread far beyond people with
German ancestry. Here's an example. I keep my car in a parking
garage run by Arab-Americans in the South Loop area of downtown
Chicago. Near the entrance of the garage is a sign announcing
that hand car washing is available; various options and prices
are listed, and then the sign ends with:
Please let attendent know
"Leave key with"
Now, I believe the punctuation of the last line is an example of
the nonstandard but extremely common use of quotation marks to
indicate emphasis (rather than, say, ironic distancing by the
sign painter).
Amy Dahlstrom
Univ. of Chicago

Several people have posted references to constructions such as "er kommt
mit" as containing a null object or "ending a sentences with a
preposition." I contend that it is neither; while it is clearly true
semantically (how can you come along if there is no one to come along
with?) the "mit" in "mitkommen" is no more a syntactic preposition than the
English "by-" in "bypass." Mitkommen is an intransitive verb in its own
right, not the mere combination of "mit" and "kommen." Else it
would be a bit difficult to explain why "null-subject prepositions" must
occupy the node which immediately precedes the finite verb, while common
prepositional phrases can move freely:
Er kommt nicht mit uns ("generic" negative)
Mit uns kommt er nicht (he'll go, but not with us)
Er kommt nicht mit
*Mit kommt er nicht
Mitkommen will er nicht
Note that the *only* situation where "mit" can move from the head of the
verb node is when kommen/mitkommen is nonfinite, the same environment in which
it can no
longer be separated from the verb at all. Thus, when the nonfinite
"kommen" is moved, mit- has to "come with." IMNSHO, this is fairly strong
evidence that "mit" is bound to the verb, which has been found to be
"happiest" at the end of a clause (as seen in dependent clauses). A "null
object," on the other hand, could just as easily have appeared anywhere
where an explicit object could have appeared. It also fails to account
for the numerous situations in which "dangling prepositions," while
common in English, are absent in German:
I need someone to work with
*Ich brauche jemanden zu arbeiten mit
Ich brauche jemanden, mit dem ich arbeiten kann
I need someone with whom I can work
While the outcry against "dangling prepositions" in English may be a
prescriptive rule up with which we cannot put, it is surprisingly
descriptive of German once the preposition look-alikes in
separable-prefix verbs are accounted for.
Jeff Bishop
jbishopnwu.edu

In regards to the null-object discussion, here is an interesting example in
vernacular usage in English, at least amongst my peers:
S1:I'm going to the beach.
S2: Can I go with?
--Becca Gross
UMASS/Amherst